Guard efficiency compensation system and method

Abstract

A liquid scintillation counting system employs a guard detector efficiency compensation system to adjust sample event counts to compensate for a non-ideal guard which may not detect all cosmic and environmental gamma background noise events. The system and method determines counts of events detected coincidently by a guard detector subsystem and a sample detector subsystem in one or more energy regions as well as counts of events that are detected by the sample detector subsystem and not coincidently detected by the guard detector subsystem for the respective energy regions. The system and method calculates correction values for the respective energy regions based on the counts of coincident and non-coincident events and the guard efficiency values associated with the respective energy regions, using, for example, a quenched or unquenched sample. The system then applies the calculated correction values to counts for the respective energy regions, to produce corrected sample event counts.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 61 / 981,266, which was filed on Apr. 18, 2014, by Richard R. Harazin for a GUARD EFFICIENCY COMPENSATION SYSTEM and is hereby incorporated by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a liquid scintillation counting system and, more specifically, to a guard efficiency compensation system and method for a scintillation counting system.[0004]2. Background Information[0005]Liquid scintillation counting systems are utilized to count radiation events in a sample being tested. Such systems often utilize a lead shield to block or inhibit background radiation, from the environment, which could cause unwanted noise events to be included when counting events in the sample. Typically, the lead shield is thickest at the top of the liquid scintillation counting system where cosmic ray flux is most i...

AI Technical Summary

Benefits of technology

The present invention is related to a liquid scintillation counting system and a method for improving its accuracy and efficiency. The invention is about a system and method for detecting radiation events in a sample using a lead shield and a guard detector compensation system. The system includes a sample detector subsystem and a guard detector subsystem. The guard detector compensation system uses pre-determined guard efficiency values to adjust sample event counts and compensate for non-ideal guard performance. This improves the accuracy of the sample event counts and allows the system to operate efficiently in an environment where the sample is less isolated during evaluation. The invention also includes a flowcharts and a table to describe the system and method in more detail.

Problems solved by technology

Such systems often utilize a lead shield to block or inhibit background radiation, from the environment, which could cause unwanted noise events to be included when counting events in the sample.

However, as more lead is added, the overall system becomes heavy and cumbersome.

However, due to the non-ideal performance of the guard subsystem, not all background noise events are coincidently detected, and thus unwanted background noise events may still be inadvertently included in the count of events in the sample.

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